Harvested crop take-up arrangements are used in agriculture both to take up harvested crop lying on a field that may have been dried previously and was deposited in a swath, and to conduct it to a harvesting machine in which it is: baled into a bale (baler), deposited (self-loading storage box), chopped (forage harvester) or threshed (combine). Usually such harvested crop take-up arrangements include take-up drums with tines attached to tine carriers extending transverse to the forward operating direction. The tine carriers are brought into motion in that they themselves or a central shaft connected to them is brought into rotation. The tine carriers are controlled by curved tracks or cam tracks or they may be uncontrolled. The tines extend outward through intervening spaces that remain between strippers attached to the frame of the take-up arrangement, and move along these intervening spaces.
Usually a so-called hold-down is arranged above the take-up drum which limits the movement of the harvested crop conveyed by the take-up drum in the forward and upward direction. Such hold-downs are configured, in the art, by flat sheet metal plates (DE 39 19 889 A) or arrangements with two or more rolls rotating freely or driven and arranged transverse to the forward operating direction (DE 39 22 695 A) or rolls with sheet metal plates following downstream connected in joints, free to pivot, or resilient tines (DE 101 20 124 A).
It has proven to be advantageous to configure the hold-down so that it can be raised by means of an active drive, in order to permit it to clear after a jam in the flow of harvested crop, so as to simplify the clearance of the harvested crop during a reverse operation. For this purpose a hydraulic cylinder is provided between the frame retaining the take-up drum and the hold-down. (EP 0 403 899 A, DE 199 18 552 A).
The take-up drum itself is coupled to the chassis of the harvesting machine, free to pivot, about a horizontal axis extending transverse to the forward operating direction and is guided across the ground at a constant height by means of support wheels or active actuators controlled by means of a ground distance sensor (see DE 41 15 056 A, DE 100 57 135 A or DE 299 22 193 U). For operation on public roads the take-up drum is pivoted upwards about the aforementioned axis by means of a hydraulic cylinder. In case that the hold-down is then in a raised position there is a danger that it could collide with some of the components of the harvesting machine, for example, the underside of the frame of the harvesting machine or a towbar by means of which it is coupled to a towing vehicle. Accordingly, the operator of the harvesting machine must watch that he/she lowers the hold-down before he/she raises the take-up drum, in order to avoid any damage to the hold-down or to the harvesting machine. This task is prone to error, particularly for inexperienced or tired operators.